556- Primary fuel pump circuit failure

Every couple months my car would stumble, sputter, die and then be fine after 30 minutes for another couple months or so. Well the car decides to do this to me on an all mustang Poker Run, embarrasing , but atleast it finally threw me a code. What was originally presumed to be a PIP sensor on the way out turns out to be the CCRM.

I would check for power at the few pins involved, but since it is an intermittent problem I doubt I would find anything. So, I should check the wires for any cracks and breaks, but otherwise just replace the CCRM. Just want to make sure I dont go spend about $200 and then in two months get stranded at a carshow.

I replaced the CCRM with a remanufactured one from napa for $125. Thought it was fixed, drove 20 miles away from my house and it died. took me 3 hours to get home breaking down in the street over and over. I am so ****ed.

I cant get that link to work, but I found a write up on the CCRM that you did on Mustang Tech yesterday. Thank you I tried to do some of the tests this morning but I had confusing results. am i supposed to probe the pins from the back of the plug while its plugged in? Or unplug and probe the pins from the front?I dont even know if thats the problem anymore, or if now I may have fried the new CCRM.

I also have a code 565 - canister purge circuit failure. This is the thing plugged into the wiring harness at the top of the passenger side firewall with a vacuum line in and out. right? Could this be the problem?

Ill check for new codes again tomorrow. Its better I not be near my car right now

You have to probe the wires while the connector is plugged in. While the car is off, push a pin through the wires you want to test; I recommend only doing a couple of wires at a time. If you're testing for voltage, you want the positive lead on your voltmeter on the pin and the negative on a ground somewhere. The radiator support is a good spot, there's a ground wire screwed in right where the hood prop rod pivots from.

You are correct on the CANP. However, it only allows gas vapor from the charcoal canister in the fender to flow into the intake manifold. It has nothing to do with the problems you're having.

All you can do is test the CCRM wiring when it's having a problem. That way you'll know for sure. I had the same problem with my old V6, and the only way I found out it was the CCRM was to carry my voltmeter with me as I drive around. When the car died, I tested the wiring right away. In my case, I has power going into the CCRM, none coming out.

SN Certified Technician

I use a safety pin wrapped in electrical tape (for shorting protection). I leave the end of the safety pin exposed so I can clip my aligator clip on it (my meter lead is plugged into the aligator clip).

If you would like to try and have a work-around in place (do this at your own risk. I don't recommend driving the car like this):

You could make a little harness. Cut a piece of 12 AWG wire. Connect one end to the battery and put a 20 amp fuse on it. Remove the fuse till later. Connect the other end of the wire to CCRM Pin 5's wire. Because there's no fuse, the circuit you added is useless for now.

If the car craps out and CCRM Pin 5 (DG/Y) doesnt show power while it should, install the fuse and see if your fuel pump magically comes to life. If so, you're onto something and can diagnose it further.

By doing this, you are bypassing the CCRM relay and manually applying power to the wire that goes to the fuel pump. If this doesnt help, the issue might be the intertia switch, plug at the tank or the FP itself (or the ground at the pump).

I installed a wire going from the possitive to pin 5 with an inline fuse (Genius!!!, thank you). I drove it around all last week and finally got it to break down again. installed the fuse, and it didnt change a thing. Went to the rear of the car and I could hear the fuel pump. Checked the fuel pressure at the fuel rail and all was good. So, unless I have over looked something, fuel is not my problem.

KOEO, I checked the plug going to the coil, and there was 6 volts. When cranking there was 12. pulled the #1 plug wire off the distributor and there was no spark jumping from the distributor cap to the intake manifold while cranking. tried again holding the coil wire close to the intake manifold and there was a very weak intermittent spark. So, does this mean the coil is bad? Or are there other parts that could be at fault?

SN Certified Technician

Six volts at the coil is disturbing. It should be 12 V any time the key is on (the positive side of the coil receives constant accessory power from your EEC relay. The computer only controls the ground to the coil). Couple that with a weak looking spark (if it's weak at 1 atm with no fuel on it, imagine how bad it would suck inside the chamber).

I would confirm the weak voltage to the coil (the six volts). You might have an electrical issue before the coil. Once that's square, if your spark still looks like crap (charge the battery and look for a blue spark. I pull a plug wire and install an old plug gapped at 0.070". Then ground the threads of the plug and watch the spark). If your spark is red or orange and the battery is charged (and there's 12V+ volts going to the coil), swap a spare coil on.

The other issue you might find is that your TFI is going out. This would show up as an intermittant ground pulse going into the coil's electrical connector (that's not the only reason for a bad ground pulse, but it is a sign and reason to go have the TFI repeatedly bench tested).

The spark was orange, but when I hooked up everything normal and pulled the #1 wire off the dist cap it arcs to the intake manifold blue... So maybe I set up something wrong for my spark test? and all of this was just a test run to see how everything should be while the engine is working properly